This invention relates to chemically modifying the surfaces of polymeric materials.
A number of polymers useful in the biomedical field, e.g., for storing, dispensing, handling, or transferring materials such as drugs, proteins, biological macromolecules, and vaccines contain hydroxyl or carboxyl groups (or both) either as end groups or side groups along the polymer chain. Examples of polymers (including elastomers, rubbers, or plastics) having hydroxyl or carboxyl side groups include poly(hydroxyethyl methacrylate) and polyvinyl alcohols. Polymers having hydroxyl or carboxyl end groups include polyesters, polycarbonates, polylactones, polyurethanes, polyacetals, polyethers, silicones, and polyamides (e.g., nylons). In addition, polymers crosslinked using crosslinking agents such as diols and dihydroxy phenols will contain terminal hydroxyl groups.
One problem associated with these polymers is the deposition of materials such as proteins, biological macromolecules, drugs, or vaccines on the surface of the polymer due to hydrogen bonding between the deposited material and surface hydroxyl or carboxyl groups. Such deposition limits the usefulness of these polymers because the adsorbed materials are often very costly. Lim et al., U.S. Pat. No. 4,569,858 describes improving the soil resistance, e.g., to proteins, of a contact lens made from a hydrophilic polymer having surface hydroxyl and carboxyl groups by either treating the lens directly with reagents such as diazoalkanes, dimethylformamide dialkyl acetals, and the reaction product of alkylenediisocyanate and polyethylene glycol monomethyl ether, or by pretreating the lens with a strong base followed by treatment with a relatively high molecular weight acylating agent (e.g., neodecanoyl chloride or pivaloyl chloride).